Particle spraying device

ABSTRACT

A multiple screw auger mounted at the bottom of a hopper carries the particles to a spray device which extracts the particles from the outlet end of the auger and directs them in a predetermined pattern toward a workpiece.

United States Patent [1 1 Warning 51 Feb. 20, 1973 [54] PARTICLESPRAYING DEVICE [76] Inventor: Walter B. Warning, 2424 N. Nordica Ave.,Chicago, 111. 60635 [22] Filed: June 24, 1971 [21] Appl. No.: 156,232

[52] US. Cl. ..239/654, 239/675, 239/424.5 [51] Int. Cl ..A01c 3/06 [58]Field of Search ..239/694, 669, 675, 418, 423,

[56] References Cited UNITED STATES PATENTS 1,970,021 8/1934 Peters etal. ..302/50 X 3,152,065 10/1964 Sharp 61 al.".

1,128,043 2/1915 Quigley .222/413 UX 2,127,693 8/1938 McCanless et a1....302/50 2,315,079 3/1943 Reeves ..302/50 Primary Examiner-Allen N.Knowles Attorney-Raymond E. Fidler et al.

[ 5 7 ABSTRACT A multiple screw auger mounted at the bottom of a hoppercarries the particles to a spray device which extracts the particlesfrom the outlet end of the auger and directs them in a predeterminedpattern toward a workpiece.

8 Claims, 8 Drawing Figures PATENTE FEBQD 1m 7 l 7, 7 52 YSHEET 10F 2FIG. 3

FIG. 2

INVENTOR WALTER B. WA RN/NG ATTORNEYS PATENTEDFEBZOIQYS SHEET 2 [IF 2FIG. 6

INVENTOR WALTER B. WARN/N6 BY 7 ATTORNEYS PARTICLE SPRAYING DEVICE Thepresent invention generally relates to the art of spraying particulatematter onto a workpiece, and it relates more particularly to a new andimproved method and apparatus for providing a uniform dispersement ofparticles in any one of a plurality of preselected patterns.

In the past, various methods and techniques have been employed forapplying a coating of particulate matter to the surface of a workpiece.Gravity, air jets and electric fields have all been used for thispurpose, but except when highly complex and expensive equipment has beenemployed, uniformity of particle distribution has'not been achieved.Variations in size, surface configuration and moisture content of theparticles has resulted in irregular spray patterns and in some cases incomplete interruption of the particle spray.

Another disadvantage of the prior art devices is the limited applicationof any particular piece of equipment without extensive modification.Many of the earlier devices had to be custom designed and built for aparticular use. It would be desirable, however, to provide a particlespray device which could be used with different types and sizes ofparticulate matter and which could be readily adjusted to provide anyone of a plurality of different spray patterns.

Accordingly, a principal object of the present invention is to provide anew and improved method and apparatus for spraying particulate matter.

Another object of this invention is to provide a new and improved devicefor providing a uniform spray of solid particles.

A further object of this invention is to provide a particle spray devicehaving readily changeable means for varying the spray pattern producedthereby.

A still further object of this invention is to provide apparatus forapplying a coating of food particles to the surface of an article.

Briefly, the above and further objects may be realized in accordancewith the present invention by providing an auger for carrying particlesfrom a hopper or the like to a spray means located at the outlet end ofthe auger for extracting the particles from the auger and directing themin a predetermined pattern toward the workpiece. The spray means may bea plurality'of spray orifices mounted in proximity to the outlet end ofthe auger to create a small vacuum just forward of the auger whichextracts the particles therefrom. Preferably, the spray orifices areprovided in a removable plate mounted over a manifold plate to permitthe facile exchange of plates to alter the spray pattern.

In accordance with another aspect of this invention, the spray device ismounted adjacent to a turntable disposed along a conveyor belt. Articlesof food, such as cakes, are fed to the turntable which is rotated duringoperation of the spray device to apply a coating of food particles suchas crumbs to the sides of the cakes.

Further objects and advantages and a better understanding of theinvention may be had from the following detailed description taken inconnection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a system embodying the present inventionfor applying a coating of food particles to the sides of the cakes;

FIG. 2 is a side elevation, partly in cross section of the coatingstation in the system of FIG. 1;

FIG. 3 is an enlarged, sectional view of the spray mechanism employed inthe device of FIG. 2;

FIG. 4 is a front view of the spray mechanism of FIG.

FIG. 5 is an exploded, perspective view of a spray assembly embodyingthe present invention;

FIG. 6 is a cross-sectional view of another embodiment of the presentinvention;

FIG. 7 is a front end perspective view of another spray device embodyingthe present invention; and

FIG. 8 is a cross-sectional view of still another embodiment of thisinvention.

The present invention is primarily described herein in connection withthe application of a coating of edible particles. Inasmuch as suchparticles are moisture absorbent and generally vary in size, shape anddensity, it is particularly difficult to apply a relatively uniformcoating thereof to another article. Moreover, for reasons of economics,a spray device for the application of food particles should be readilyadaptable for use with particles of differing size, density, shape andcohesiveness, and in addition, the spray pattern and concentration ofthe particles therein should be adjustable. It will be apparent,therefore, that the method and apparatus hereinafter described may beused with most other types of solid particulate matter such, forexample, as dry paint particles, textile fibers and reflective flakematerial.

Referring now to the drawings and particularly to FIG. 1 thereof, aconveyor belt 10 carries a plurality of cakes 11 in seriatim to a spraystation 12 wherein a coating of food particles such, for example, ascrumbs, nut fragments, granulated sugar or the like, is applied to theside surface of the cakes 11 and a conveyor belt 13 carries the coatedcakes to another station. As shown, the individual cakes 11 are disposedon circular trays 14 for convenience in handling. The coating station 12includes a rotatably mounted turntable 16 which is driven through achain and sprocket assembly 17 by an electric motor 18. A particlesprayer 20 mounted adjacent to the turntable 16 includes a hopper 21containing the particulate matter and a spraying head 22 for directing auniform, preselected pattern of particles toward the vertical side ofthe cake disposed on the turntable 16.

The system shown in FIG. 1 is of the semi-automatic type utilizing anoperator located at the coating station who transfers the cakes from theconveyor belt 10 to the turntable platform 16 and manually initiatesoperation of the coating mechanism to energize the motor 18 and causethe device 20 to produce the spray of particles. Preferably, althoughnot necessarily, the period of operation of the spray device 20 isautomatic and is preset to provide the desired thickness of coating onthe cakes. After the coating has thus been sprayed onto the cake locatedon the turntable 16, the operator transfers that cake to the conveyorbelt 13 and transfers the next uncoated cake from the conveyor belt 10onto the platform 16. It will be apparent to those skilled in the art asthe present description proceeds that the spray device 20 may be locatedand the spray pattern preselected so as to coat not only the sides butalso the top of the cake on the platform 16. Similarly and if desired,another spray device 20 may be provided further down the line forspraying a different particulate substance onto the cakes 1 1.

Referring to FIG. 2, it may be seen that a multiple screw auger 25 isrotatably mountedin a rigid tube 26 disposed in the bottom of the hopper21 which, as best shown in FIG. 1, has sloping bottom side walls 24. Thetube 26 is, open along the top so that the particulate matter containedin the hopper 25 is fed by gravity into the spaces between the flutes ofthe auger. The rear end of the auger is provided with a shaft 27 onwhich is mounted a sprocket 28 which is connected through a chain 29 toa drive sprocket 30 mounted on the shaft of an electric motor 31. Asuitable sealing gland is provided between the rear wall of the hopper21 and the auger shaft 27 to prevent leakage from the hopper. Theforward end of the tube 26, as best shown in FIG. 3, extends through anopening 34 in the front wall 35 of the hopper 21 and provides theforward bearing for the auger 25. The auger, however, extends forwardlybeyond the front edge of the tube 26.

An annular manifold plate 36 is secured as by bolts to the wall 36 overthe forward end of the tube 26 and is provided with an annular groove 37in the forward face thereof. An air tube 38 connected to a suitablesource of compressed air is connected through a fitting 39 to the backface of the plate 36 below the hopper and is connected by a drilledpassageway 40 in the plate 36 to the groove 37. An orifice plate 41 isremovably attached as by means of bolts 42 over the forward face of theplate 36 and is provided with a central opening 44 into which the outletend of the auger extends. A plurality of small diameter orifices 45 aredrilled through the plate 41 so as to communicate with the groove 37.The number, direction and position of the orifices 45 determine thespray pattern which is produced when the motor 31 is energized andcompressed air is supplied to the spray assembly 22. For ap plying acoating to the sides of a cake as illustrated in the system of FIG.'1, aconical pattern is preferred and, therefore, the orifices 45 aresymetrically arranged in a circle surrounding the opening 44 as shown inFIG. 4.

In order to assure that the particles are uniformly dispersed throughoutthe spray pattern, the auger 25' should be of he multiple screw typehaving three or four flutes. Moreover, the spray assembly 22 should beas close as possible to the hopper so as to minimize the effect ofsettling of the particles in the auger from the time they leave thehopper to the time they are picked up by the air jets from the orifice45 a nd sprayed onto the workpiece. An added advantage of mounting thespray mechanism at the hopper and utilizing the particle spray means toextract the particles from the outlet end of the hopper is thatcompacting of the particles in the auger and clumping and clogging areeliminated. Moreover, the auger provides a positive feed for theparticles so that for a given speed of rotation of the auger 25 a givenamount of the particulate matter is sprayed onto the workpieceirrespective of variations in the size, shape and moisture content ofthe particles.

Although, the particular control circuit utilized with the spray deviceof the present invention may utilize standard control devices, where thedevice 20 is operated intermittently as, for example, in the system ofFIG. 1, the valve which controls the supply of air to the manifold plate36 should be opened before the motor 31 is energized to drive the augerthereby to avoid spraying an excessively heavy coating onto theworkpiece when the coating device is initially ener gized.

As explained in connection with FIG. 3, the orifice plate 41 is quicklyand easily removed from the manifold plate 36 whereby different orificeplates 41 for providing different spray patterns may be easilyinterchanged. The spray assembly 22 as shown in FIG. 5, includes anadapter plate 41a wherein the orifices are positioned so as to produce aflat spray pattern. As there shown, the orifices45 are located only atthe horizontal sides of the center opening 44 thereby to provide a spraypattern which is generally rectangular in cross-sectional shape having ahorizontal dimension substantially exceeding the vertical dimension. Itwill be apparent that other patterns may be provided by proper locationof the orifices. Also, the diameter of the orifices may be varied fromone plate 41 to another so as to control the density of the spraypattern produced without altering the air pressure supplied to themanifold plate 36. Depending upon the size of the particles and thedistance between the spray device and the workpiece, the air pressure tothe manifold may vary between about 3 psi. for a fine dust-like materialto about p.s.i. for heavier materials.

Referring now to FIG. 6, there is shown another embodiment of thepresent invention comprising a multiple screw auger 50 mounted in thebottom of a hopper 51 within a tube 52. The central portion of the upperside of the tube 52 is cut away so that the particulate matter withinthe hopper 51 may fall by gravity into the spaces between the flutes ofthe auger 50. The auger 50 is journaled at its ends in the tube 52 andis provided with an axial bore 53 which is counterbored and tapped atthe forward end to receive an orifice fitting 54 having a slightlyflared out orifice. The rear end of the bore 53 is coupled through asuitable swivel coupling 55 to a compressed air line 56. A drivesprocket 57 is secured to the rearwardly extending shaft 58 on the auger50 for rotating the auger to feed particles at a controlled rate fromthe hopper to the forward or outlet end as shown at the right in FIG. 6.In this embodiment of the invention, as the auger 50 is rotated to feedthe particles to the right-hand end thereof, the air jet eminating fromthe bore 53 creates a vacuum or low pressure area at the outlet end ofthe auger to extract the particles therefrom and to direct them in apattern which is generally circular in cross-sectional shape. It will beapparent that the shape of the orifice in the fitting 54 isdeterminative of the size of the pattern produced at any given distancefrom the outlet end of the auger. This embodiment of the inventionprovides a spray pattern which is necessarily circular incross-sectional shape but the diameter of the pattern at any givendistance from the orifice may be adjusted by varying the pressure to theline 56 or by interchanging spray nozzle pieces 54 having differentdegrees of flare and different orifice diameters.

In order to provide a non-circular pattern using the auger and sprayorifice as shown in FIG. 6, a non-circular pattern control tube may bemounted on the hopper over the outlet end of the auger. In FIG. 7 such atube 60 is shown in use with a plurality of augers 50 mounted side bysideand each including a control air spray orifice 54. The use ofmultiple augers enables a greater uniformity of particles in the spraypattern than is achieved using a single auger.

The pattern control tube 60 provides a horizontally elongated generallyrectangular pattern. It will be apparent that pattern control tubes ofother shapes may be used to replace the tube 60.

Referring to FIG. 8, there is shown another embodiment of the inventionwherein the need for a source of compressed air is obviated and in itsplace is provided a rotating flared-out member 63. The flared out member63 has a hub portion 64 having connected thereto a drive sprocket 65which is driven through a chain 66 by a sprocket 67 connected through astep-up gear train 68 to an electric motor 69 which also drives theassociated auger. As in the previously described embodiments, the sprayproducing means of FIG. 8 is located directly at the outlet end of theauger in close proximity to the hopper, and being operated at a highangular velocity of the order 500 to 5,000 rpm. creates a low pressurearea at the outlet end of the auger thereby to extract the particlestherefrom and direct them in a desired pattern onto the workpiece. As inthe embodiment of FIG. 6, the pattern produced by the device of FIG. 8is necessarily circular in cross section but the diameter of suchpattern may be adjusted by interchanging the member 60 with members 63having different shapes and angies of divergence.

Depending upon the nature of the particulate material being sprayed andthe electrical characteristics of the workpiece, the spray means may beof the electrostatic type which produces an electric field for directingthe particles toward the workpiece. In accordance with the presentinvention, such a spray means should be located in close proximity tothe outlet end of the auger which, in turn, should be located inproximity to the hopper thereby to avoid the several problems heretoforementioned.

While the present invention has been described in connection withparticular embodiments thereof, it will be understood that those skilledin the art may make many changes and modifications without departingfrom the true spirit and scope thereof. Accordingly, the appended claimsare intended to cover all such changes and modifications as fall withinthe true spirit and scope of the present invention.

What is claimed is:

1. Apparatus for spraying particulate matter in a predetermined patternonto a workpiece, comprising a hopper having from and rear walls,

an auger rotatably mounted in the bottom of said hopper with the outletend of said auger proximately disposed with an aligned opening in saidfront wall, spray means mounted at said front wall for directing astream of gas across the outlet end of said auger toward said workpieceto extract particles from said auger and carry them in a predeterminedpattern onto said workpiece. 2. Apparatus according to claim 1 whereinsaid last named means comprises a plurality of orifices disposed inproximity to said outlet end of said auger, and means supplying gasunder pressure to said orifices. 3. Apparatus according to claim 1wherein said last named means comprises a first annular plate having anopening aligned with said auger,

said plate having a manifold groove therein, a second annular platemountedover said first plate and having a plurality of holes extendingtherethrough and opening at one end onto said groove, and means forsupplying gas under pressure to said groove, whereby the gas emittedfrom said holes sprays said particulate matter toward said workpiece. 4.Apparatus according to claim 1 wherein said auger has a plurality offlutes.

5. Apparatus according to claim 1 comprising a plurality of said augersmounted in side by side relationship at the bottom of said hopper. 6.Apparatus according to claim 5 comprising a flared out membersurrounding the outlet end of said augers for controlling the spraypattern produced thereby. 7. Apparatus according to claim 1 wherein saidlast named means comprises a divergent tubular member rotatably mountedover and in alignment with said outlet end of said auger, and means forrotating said tubular member. 8. Apparatus according to claim 7 whereinsaid tubular member is provided with a plurality of helical flutesdisposed on the inner wall thereof.

1. Apparatus for spraying particulate matter in a predetermined patternonto a workpiece, comprising a hopper having front and rear walls, anauger rotatably mounted in the bottom of said hopper with the outlet endof said auger proximately disposed with an aligned opening in said frontwall, spray means mounted at said front wall for directing a stream ofgas across the outlet end of said auger toward said workpiece to extractparticles from said auger and carry them in a predetermined pattern ontosaid workpiece.
 1. Apparatus for spraying particulate matter in apredetermined pattern onto a workpiece, comprising a hopper having frontand rear walls, an auger rotatably mounted in the bottom of said hopperwith the outlet end of said auger proximately disposed with an alignedopening in said front wall, spray means mounted at said front wall fordirecting a stream of gas across the outlet end of said auger towardsaid workpiece to extract particles from said auger and carry them in apredetermined pattern onto said workpiece.
 2. Apparatus according toclaim 1 wherein said last named means comprises a plurality of orificesdisposed in proximity to said outlet end of said auger, and meanssupplying gas under pressure to said orifices.
 3. Apparatus according toclaim 1 wherein said last named means comprises a first annular platehaving an opening aligned with said auger, said plate having a manifoldgroove therein, a second annular plate mounted over said first plate andhaving a plurality of holes extending therethrough and opening at oneend onto said groove, and means for supplying gas under pressure to saidgroove, whereby the gas emitted from said holes sprays said particulatematter toward said workpiece.
 4. Apparatus according to claim 1 whereinsaid auger has a plurality of flutes.
 5. Apparatus according to claim 1comprising a plurality of said augers mounted in side by siderelationship at the bottom of said hopper.
 6. Apparatus according toclaim 5 comprising a flared out member surrounding the outlet end ofsaid augers for controlling the spray pattern produced thereby. 7.Apparatus according to claim 1 wherein said last named means comprises adivergent tubular member rotatably mounted over and in alignment withsaid outlet end of said auger, and means for rotating said tubularmember.